SW Smith and others design Enforcer based LSM for protection of the integrity of Linux file system[24], it provides the functions of the following aspects: provide high-level protection to software and sensitive data, when each file open , It can detect whether the document was changed, when the file was tampered with the document, it sets log on the TPM, denied access to the documents ;store encrypted retrospective file system, the encrypted information make file system was not easy to be changed; the binding of special paper, make that only a special application to access them, which means that even if someone endanger the system, the attacker cannot steal important documents.